1. Field of the Invention
The present invention relates to an apparatus which generates an abridged map which has been produced by simplifying a road map.
2. Description of Related Art
There is a known method for simplifying the shape of a road based upon map data for displaying a map. For example, with the apparatus disclosed in Japanese Patent laid-open application Publication No. 11-202762, the shape of the road is simplified by performing procedures such as straightening and orthogonalization and the like upon the links which specify the road shape in the map data, and by displaying only landmark information within a range which is regulated by a mask. A map which is more easily viewed than a normal map is provided by displaying an abridged map generated using the road shape which has been simplified in this manner.
Moreover, an apparatus is also known which displays shorelines upon a map when displaying the map information upon a screen (for example, Japanese Patent laid-open application Publication No. 62-153888).
However, with the apparatus disclosed in Japanese Patent laid-open application Publication No. 11-202762, although the abridged map is generated by simplifying the road shapes by performing procedures such as straightening or orthogonalization or the like with respect to each of the links, the shapes of the shorelines are not simplified. Furthermore, with the apparatus disclosed in Japanese Patent laid-open application Publication No. 62-153888, although it is possible to display the shorelines upon the map, the shapes of the shorelines are not displayed after having been simplified. Accordingly, there is a demand for an apparatus which can display shorelines upon a map after having simplified them so that they are easier to see.